Binding agents based on aqueous alkali metal silicate solutions have been known for a long time and are used to a great extent in practice. They are used, inter alia, for producing mineral insulating materials, impregnating agents, coating compounds, paints and cements, and for glueing wood, paper, ceramics and mineral material.
When alkali metal silicate solutions alone are used for the said purposes, that is without an additive, the adhesive and cement compounds, insulating layers, coatings and paints produced therewith in many cases do not fulfill the many technical requirements. Thus, there is frequently a deficiency in the hardness, elasticity and resistance to temperature and water. Therefore, a large number of proposals have already been made for improving these properties by suitable additives to the binding agents. In particular, acids, and products which generate acid or which react acid, such as urea, have been proposed as hardeners. However, the large number of known proposals show that the effects obtained in practice are still unsatisfactory.
Another approach has been to incorporate other compounds which harden with reaction, such as mixtures of alkali metal silicate solutions with triglycidyl isocyanurate and, water-soluble amines, and water-soluble quaternary nitrogen compounds, as described in U.S. Pat. No. 3,778,283 to von Freyhold, commonly assigned.